Potential of Dynamic Creep to Predict Rutting

Rutting is one of the predominant types of distresses observed in hot mix asphalt. Different versions of creep tests are used at present to evaluate rutting potential of hot mix asphalt mixtures. To evaluate the potential of dynamic creep to predict rutting, tests were conducted under representative conditions on laboratory samples with different levels of air voids and on field cores from pavements with known rut depths. Test were also conducted on mixes with different aggregates and aggregate gradations to identify mixes with rutting potential. When subjected to dynamic creep, samples with different air voids showed a similar response to that observed in field rutting. Good correlations were obtained between permanent creep strain and rutting rates of pavements. The dynamic creep test was able to quantify the effect of aggregate type and gradation on rutting potentials of mixes. Mixes with crushed aggregates performed better in the creep test than the mixes with uncrushed aggregates.